1. Field of the Invention
The invention relates to a multi-stage planetary drive.
The function of planetary drives is known. A sun gear is located in the center, which is driven by a motor, which is connected via a motor flange to the planetary drive. The sun gear transfers its motion to at least three revolving planet wheels forming a gear speed, which are arranged on bearing pins of a pinion cage. In case of several gear speeds the last pinion cage is connected to a driven shaft in a fixed manner and this way ensures the transmission of force at the driven side. At the exterior the planet wheels travel in an annulus gear connected to a housing in a torque-proof manner. Further, the housing is connected at the driven side to a driven flange.
2. Background of the Invention
The current state of knowledge is as follows.
The object of the invention is a multi-stage planetary drive with increased efficiencies, both in utility and cost, compared to such gears commercially available today.
With regard to the noise developing during the operation of a spur gear transmission it is known to provide the transmission arrangements with helical gears in order to allow a lower-noise operation. However, even in this way satisfactory noise behavior cannot be achieved in all cases, particularly in multi-stage planetary drives with simultaneous helical and spur gears.
Further, such multi-stage planetary drives are elaborate and expensive in their production, because the sprockets used as annulus gears with a spur gearing and a helical gearing must be screwed to each other and/or adhered to each other in order to form a one-part and/or two-stage sprocket before a sprocket formed in this manner can be accepted in a housing of the planetary drive.
The problem addressed by the invention is to provide a multi-stage planetary drive that operates at a lower noise level, and providing a simpler and more cost-efficient assembly mechanism than those currently available.